Projectile.



E. GATHMANN.

Pateflted NOV. 17, 1908. 7

EMIL GATHMANN, O1 BETHLEHELl, PENNSYLVANIA;

PROJECTILE.

Specification of Letters Pasent.

Patented nov. 17, 1908.

Application filed December 7,1907. Serial in. 405,488.

To all whom it may concern:

Be it known that I, EMIL GATHMANN, a citizen of the United States, residing at Bethlehem, Northampton county, Pennsylvania, have invented certain new and useful Improvements 'in ?rojectiles, of which the following is a specification.

The objects of this invention are to pre duce an armor piercing projectile containing for a given size or weight and mass of head aminimum of initial strains, bordering on rupture. x

Other objects are to provide a construction which allows of uniform and efiicient hardening and/tempering of the large, as well as the small and medium sizes of armor piercing projectiles. 7

Further objects are to improve the details of constriwtion of such projectiles.

My invention relates to that type of projectiles termed armor piercing shot and shell by those familiar with the art. The head or forward portion of these projectiles are usually made very massive, and the body or rear portion contains a cavity or explosive charge chamber. It is extremely desirable that the head or for 'ard portion of the projectile be so hardened and tempered as to enable the projectile when impacting with a suitable velocity to penetrate the extremely hard and tough armor plates produced by the Krupp and other s At the present date, 'specitiations relating to armorpiercing pro ectiles, prescribe a. test in which the projectile must perforate a hard faced armor plate equal to the Krupp standard of a thickness of at least one caliber oi diameter oi the projectile, with the requirements that there be no breaking or cracking of any portion of the latter so as to expose the charge cavi ty.

Although the armor piercing projectiles are at the ncsent time being made of high grades of alloy steels and are hardened and tempered with skill and care, a great many projectiles tail to pass the prescribed ballistic tests. The most frequently occurring manner of failures that l have personally \vit- Messed during the past seven years were due to the shattering of the head of shell and consequent exposure or opening up of the forward end of the charge cavity. This danger ot shattering or rupturing ot' the head ol the projectile upon impact. with modern armor plate becomes relatively greater, the larger the size or diameter of the projectile and the more massive the forward end orhead.

From the many ballistic tests of projectiles that I have witnessed and from a numberof experiments made, I .have determined that the shattering and rupturing of the usual constructions ,of armor piercing projectile heads, is due mainly to excessive initial strains in the mass of the metal composing the head,

which strains are caused by the rapid necessary cooling of the hardening processes, and the consequent shrinkage or contraction of the large mass of the outer portion of the metal upon the practically unyielding inner axial core or central mass of metal, which being thus subjected to a compression beyond its normal shrinkage dimensions, exerts an initial outward pressure bordering on rupture.

I have seen a great number of armo'r piercing projectiles, the points and heads of which have ruptured spontaneously within a short period of elapsed time after hardening treatment; In my improved projectile, I so construct the head portion that the internal rupturing strains due to hardening treatment as previously described; will be much reduced or p'actically eliminated. I also provide-a construction of the point of the head of the projectile hereby should the point be shattered or ci..cked, during penetration of an armor plate. the cracks or shattering action will not be readily transmitted to the major portion of the head, the danger of exposure, or opening up of the char-go cavity being thus'greatly reduced. 7

In order to obtain a good bursting etfec-t. of the projectile due to the explosion of the cavity charge of explosive material, it is essential that the cavity be strongly inclosed and that no openings exist through which the gases would readily issue without properly fragmenting the shell. 1

Several forms of the invention are illustrated in the accompanying drawings, in which Figure 1 is a longitudinal central section of a a projectile embodying the invention. Fig. is a longitudinal central section of another shell embodying the invention.

Similar letters represent like throughout the drawings.

The iractically cylindrical bod A of'the n'ojectile contains a charge cham or 13 provided at its rear end with a threaded por: tion C adapted to engage with a suitable parts base plug 1). The relatively massive head E isprovided with a centrally located longitudinal bore F, said bore extending from the forward end G of the head E 'closely'to, or into the charge chamber B, barrier block H being provided to separate the charge chamber B from the bore Rsaid barrier block H being integral with the projectile when the bore F does not extend or open into the chamber B, as shown in Fig. 1.

When the bore F'extends into the charge chamber B as shown in Fig. 2, the barrier H is suitably secured at or near the forward end'of the charge chamber B. The barrier maybe built up as shown by bushing M and plug N, and the said plug N may be adapted to carry a shell fuse 0 if so desired.

In assembling the projectile a point I is secured to the forward end G- of the head, a washer K, being preferably inserted between the said point and head. i A cap L of any desired form is then preferably placed over the said point I, the cap being locked to either the point I or the head E of the projectile in any of the usual ways. The cap L may'however be omitted in certain type of projectile in which case I prefer to use a thicker washer K as shown in Fig. 2. I-

prefer to center and fasten the point I to the head E by means of a shank P which extends from the said point I and is adapted to enter into the bore F a suitable distance to insureof proper guiding and support. The contact surface of the rear part of the point I and the forward part G of "the head E is preferably slightly cone 'shaped, the washer K being formed to fit The point said coned or tapered surface. I ispreferably fitted to the head E of the projectile after the latter hasbeen hardened andtempered, the point I being itself hardened and tempered before assembling to the head of the projectile.

In hardening the head E of my construction of'projectile, the mass of metal will contract inwardly in the usual manner due to rapid coolingof the same; the bore F will however allow of aninward movement or flow of the metal as the natural decrease in the volume of the head takes place, thus initial strains such as obtain in a solid headed projectile willnot occur, as the bore F pro- .Vides for an inward flow of metal, which flow inthesolid headed projectile is. impos-- suit'the caliber of the projectile or the mass of metal in the head of the same, thus allowing for increased changes of volume. Ifiin the hardening treatment, cooling from the exterior only is desired, which method I prefer, the.bore F is plugged with a suitable material such as fire clay, asbestos or the like so that the cooling medium will not act on the same directly.

It will be evident that my invention may be embodied in many other forms than those illustrated, as obviously the shrinkage bore F may be advantageously employed in projectiles having different shaped heads and points than those shown in the drawing and specifically described :For instance; a projectile could be employed without the point I and washer K being fitted to the heat]. E, and if desired the point could be made integral with the head of the projectile.

Therefore, without limiting myself to the precise construction illustrated and de scribed, I claim z- 1. An armor piercing projectile provided with a point a charge chamber an axial bore forward of said charge chamber and a bar- I rier separating the latter from the aforesaid bore, said barrier being integral with the major mass of the projectile, but not with the point of the same.

2. An armor piercing projectile provided with a point a charge chamber in its rear and a shrinkage bore in its head portion and abarrier separating the latter from the charge chamber, the said barrier being secured to the major mass of the projectile, but not to the point of the same.

3. An armor piercing projectile provided with a point a bursting charge chamber in its rear andan axial shrinkage bore in its head portion the said bore being closed at its rear end by a barrier and at its forward end by the projectile point, the said point not being integral with the major mass of the projectile, or with the separating barrier. 4. An armor piercing projectile provided with a shrinkage chamber in its head portion and a charge chamber in its rear or body portion, a separable point covering the forward opening of the shrinkage chamberand the forward end of the head portion of the projectile, in combination with a washer having a conical bearing surface interposed between said head portion and the point of projectile.

5. An armor piercing projectile provided with an axial bore in its head portion and an explosive chamber in its body portion a bar- :rier separating the latter from the bore, a

separable point covering the forward end of the said bore and the forward portion ,ofthe head of the projectile in combination with a Washerinterposed between the said forward portion of the head and the afore said point, the surfaces of contact of said llf) . conical with a charge chamber in its body portion --from the same by a barrier, a hard metal point covering said bore and centered on the projectile by v means of a shank extending into said bore.

7. An armor piercing projectile provided and a shrinkage chamber in its head portion, a barrier separating said chambers located at the rear end of the said shrinkage chamber a -body of hard metal covering and extending into the forward portion of the said shrinkage chamber, said body being separated from and not in contact with the aforesaid barrier as and for the purpose specified.

8. An armor piercing projectile provided with a charge chambera shrinkage chamber forward of said charge chamber, and separated from the same by a barrier, a body of hard metal coverin and extending into the forward portion oi the-shrinkage chamber said extension however not contacting with the aforesaid barrier, and a cap of relatively soft and tough material covering the said body of'ha-rd material as also a portion of the head of the projectile the cap being socured to the said head portion.

. 9. An armor piercing projectile provided with a charge chamber an axial bore forward of saidcharge chamber, and separated from the same by a barrier, a hard metal point covering said bore and centered on the projectile by means of a shank, 'andiacap of relatively soft and tough material covering the said hard metal point and also a portion of the head of the" projectile and means for fastening the cap to said head,

10. An armor. piercing projectile provided with a charge chamber an axial bore forward of said charge chamber, and separated from the same by a barrier, a hard metal point covering said bore and centered on the projectile by means of a shank, and a cap of relatively soft and tough material covering the said hard metal. point and also a portion of the head of the projectile, in comblnation with a washer interposed between the hard metal point and the said head of projectile.

EMIL GATHMANN. Witnesses ANNIE M. REINHARD, ISABEL GATHMANN. 

